Wagamama Basic Manga :

Salaryman Aizawa Haruomi hates human beings because of that, he has never gotten along with those in his company. One day, Haruomi goes to the hair salon run by his brother, but there was only Yasa, a happy go lucky, ignorant youth. Yasa is troubled because he cannot find a hairstyle model and has to practice cutting and styling real hair somehow. Since styling Harumoi’s hair, he has become his friend and they go out to eat together. It’s Haruomi who gradually opens up his heart to him.